Human 25-hydroxyvitamin D 24-hydroxylase cytochrome P450 subunit maps to a different chromosomal location than that of pseudovitamin D-deficient rickets

J Bone Miner Res. 1993 Nov;8(11):1397-406. doi: 10.1002/jbmr.5650081114.

Abstract

We have cloned part of the human 25-OHD 24-hydroxylase cytochrome P450 (P450cc24) cDNA. The characterized sequence consists of 776 bp of the coding and 720 bp of the 3'-untranslated region interrupted by an intron. In the coding region we found 79.8% similarity in DNA and 87.5% in deduced amino acid sequences between human and rat, with no similarity in the 3'-untranslated region. By Southern blot hybridization of DNA from human-hamster somatic cell hybrids and by in situ immunofluorescence hybridization, we mapped P450cc24 to human chromosome 20q13.1. This location of P450cc24 is different from that of pseudovitamin D-deficient rickets (PDDR), previously assigned to chromosome 12q14 by linkage analysis, thus excluding it as a target of the PDDR mutation. Since it is likely that PDDR is caused by a mutation in the 25-OHD 1 alpha-hydroxylase P450 subunit (P450cc1 alpha) our results do not support the hypothesis that the two cytochromes are encoded by a single gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chromosome Mapping*
  • Cricetinae
  • Cytochrome P-450 Enzyme System / genetics*
  • Humans
  • Molecular Sequence Data
  • Rats
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Steroid Hydroxylases / genetics*
  • Vitamin D Deficiency / enzymology
  • Vitamin D Deficiency / genetics*
  • Vitamin D3 24-Hydroxylase

Substances

  • Cytochrome P-450 Enzyme System
  • Steroid Hydroxylases
  • Vitamin D3 24-Hydroxylase